Trench digger



May 13, 1958 R. J. BRANT 2,334,125

7 TRENCH DIGGER Filed Jan. 5, 1954 4 Sheets-Sheet l IN V EN TOR. 490850 T 0/. 8244 May 13, 1958 R. J. BRANT 2,834,125

' TRENCH DIGGER Filed Jan. 5, 1954 4 Sheets-Sheet 2 g 0 9 9 9 9 O i? INVENTOR.

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May 13, 1958 R. J. BRANT TRENCH DIGGER Filed Jan. 5, 1954 4 Sheets-Sheet 4 A TwE/VE Y8 United States ,Patent TRENCH DIGGER Robert J. Brant, San Rafael, Calif.

Application January 5, 1954, Serial No. 402,255

3 Claims. (Cl. 37-97) This invention relates to excavating machines, and more particularly to an improved tractor-mounted excavating machine for use in digging trenches, ditches, or the like.

The main object of the invention is to provide a novel and improved excavating machine which is relatively simple in construction, which is usable on relatively steep grades, as well as on level ground, and which operates with high efficiencyin all types of soils.

A further object of the invention is to provide an improved digging wheel attachment for a tractor, whereby the tractor may be employed for excavating trenches, ditches, and the like, the attachment involving relatively inexpensive components, being rugged in construction, being easy to manipulate in accordance with the different operating conditions and in accordance with the desired depth of trench or ditch to be excavated, and being provided with speed regulating means for providing any one of a large number of different forward speeds of the tractor, as well as any one of a number of different speeds of the digging wheel.

A still further object of the invention is to provide an improved excavating machine which may be mounted on a conventional tractor with only a few alterations, the improved machine being arranged to provide selection of any one of a large number of different forward speeds of the tractor ranging from a speed of approximately 18 inches per minute to the top speed of the tractor, and the device being provided with means for regulating the speed of the digging wheel to afford a selection of four or more speeds in a high range and a selection of four or more speeds in a low range.

A still further object of the invention is to provide an improved digging machine adapted to be adjustably mounted on a tractor and being provided with hydraulic means for adjusting the machine in accordance with the steepness of the grade on which the machine is operating as well as in accordance with the direction of movement of the machine on the grade, the machine being provided with conveyor means for moving the excavated soil laterally so that it can be received in a truck or other vehicle, the machine including means for keeping the conveyor level regardless of the angle of the grade on which the machine is operating.

A still further object of the invention is to provide an improved machine for excavating trenches and the like, the machine being arranged so that the digging action of its excavating member does not depend upon the weight of the excavating member, as in digging machines of the prior art, but is controlled by the force of the weight of the tractor transmitted to the digging element through hydraulic link means, said link means being also employed to regulate the depth of penetration of the digging element into the soil, whereby the over-all length of the machine is relatively small and whereby the machine is relatively light in weight relative to its digging capacity.

Further objects and advantages of the invention will become apparent from the following description and shaft 18 to support the frame 20.

claims, and from the accompanying drawings, wherein:

Figure l is a top plan view of an improved trench digging machine constructed in accordance with the present invention.

Figure 2 is a side elevational view, with parts broken away, of the machine illustrated in Figure 1.

Figure 3 is a side elevational view showing the machine operating downwardly along a twenty-five percent grade.

Figure 4 is a side elevational view of the machine, shown operating upwardly along a forty percent grade.

Figure 5 is a longitudinal vertical cross sectional view taken through the transmission unit of the excavating machine of Figures 1 and 2.

Figure 6 is a schematic view of the hydraulic system employed in the machine of Figures 1 and 2.

Figure 7 is an enlarged cross sectional detail view taken on the line 77 of Figure 1 and showing the engagement of one of the driving pinions with the gear teeth on a digging wheel element.

Referring to the drawings, 11 generally designates a trench digging machine according to the present invention. The machine comprises a tractor 12 which may be of any suitable type, for-example, may be of the track-laying type having the endless flexible traction elements 13, 13. Pivoted at 14, 1,4 to the opposite sides of the tractor frame and extending substantially longitudinally relative to the tractor are the arms 15, 15, said arms being bent at 16, as shown in Figure 2, and being connected together by the transverse bar element 17 adjacent the bends 16, as shown inFigure 1.

Designated at 18 is a transverse shaft rotatably mounted in the ends of the. arms and having the respective sprocket wheels 19, 19 secured to the respective opposite ends thereof, outwardly adjacent the ends of the respective arms 15, 15. i

Designated generally at 20 is aframe which is rotatably mounted on the shaft 18 between the arms 15, 15, said frame comprising a superstructure having the top longitudinal elements 21, the lower longitudinal elements 22, the forward transverse connecting member 23, the rear transverse connecting member 24, and the depending rear, furrow-engaging member 25. Rigidly secured on the lower longitudinal members 22 are the vertical plate elements 26 through which the shaft 18 extends, the plate elements 26 being suitably journaled on the Rigidly secured on the transverse bar member 17 is the upstanding post element 27. Pivoted at 28 to the top end ofthe post member 2 7 is the hydraulic cylinder 29 having the piston rod 30 which, in turn, is pivotally connected to the intermediate portion of the transverse bar member 23 of frame 20, the pivotal connection being shown at 31. i The hydraulic cylinder 29 and its piston 30 define an adjustable link connecting the forward end of the frame 20 to the top end of the post member 27, and hence to the side arms 15, 15.

Designated at 32 is a belt conveyor mounted on the frame 20 and being located Within a circular digging wheel structure 33 which is rotatably supported on said frame for rotation around a transverse axis, as will be presently described. As shown in Figure 1, the conveyor 32 extends lateraily substantial distances on opposite sides of the frame 20 and is provided with suitable driving means, such as suit-able hydraulic motors, not shown, mounted in the frame ofthe conveyor and drivingly sconnected to the drive shafts 35, 35 located at the opposite ends of the conveyor, the shafts 35, 35 being coupled together by a sprocket chain 36 so that the said shafts are synchronously driven. The hydraulic motors, or other driving means employed to operate the driving shafts 35, 35 are preferably independently controlled by conventional means, not shown, whereby the speed ofthe 2,ss4,125 r belt conveyor 32may be controlled independently of the speed of rotation of the digging wheel structure 33, so that the speed of movement of the conveyor belt may be regulated in accordance with the type of soil being excavated, the speed being greater for soft soil than for relatively hard soil, whereby the soil may be transported laterally from the digging wheel as rapidly as it is excavated thereby.

It will be understood that the soil conveyed by the belt conveyor 32 will be deposited in a truck or other vehicle disposed subjacent to the end of the conveyor.

The digging wheel structure 33 comprises the circular wheel members 37, 37 which are rigidly connected together by the spaced digging buckets 38 located on and rigidly secured to the peripheral portions of the wheel elements 37, 37 andprojecting outwardly therefrom, as shown in Figure 2. The frame includes the strut elements 39 which are adjustably connected together by the rods 40 and turnbuckles 41 connecting said rods, as shown in Figure 2, the struts 39 having the rollers 42 journaled to their lower ends, said rollers being peripherally grooved to receive the inner peripheries of the respective wheel elements 37, 37. The respective wheel elements 37, 37 are formed with the inwardly directed, regularly spaced gear teeth 43 which mesh with respective pinion gears 44 journalled to the frame 29 at opposite sides of the conveyor 32. A pair of such pinion gears 44 is rigidly secured on the shaft 18, thus coupling the-wheel elements 37 to said shaft so that rotation of the shaft 18 rives the digging wheel structure 33. At the same time,

will be presently described. Thus, the elevation of shaft 18 and the digging wheel structure 33 rotatably supported on and drivingly coupled to said shaft may be controlled by means of the hydraulic jack cylinders 46.

Designated at 49 is a hydraulic pump which is drivingly coupled to the tractor engine 50, the pump 49 being in communication with a reservoir 51 containing oil or other suitable hydraulic fluid. Designated at 52 is the outlet conduit of said pump and designated at 53 is the return conduit thereof. Mounted on the tractor is a three-way control valve 54 having an inlet port 55 which is connected to the conduit 52 by a conduit 56, as shown in Figure 6. The valve 54 has a lower outlet port 57 which is connected to the lower ends of the cylinders 46, 46 by respective conduits 58, 58 and which may be placed in communication with the fluid inlet port 55 when the valve element 59 is in its lowered position, such as shown in Figure 6. The valve 54 has the upper outlet port 60 which is connected by conduits 61, 61 to the top ends of the cylinders 46, 46. When the valve member 59 is in its lowered position, shown in Figure 6, the port 60 is in communication with a return passage 61' in the valve 54, said return passage being connected by a conduit 62 to the fluid return conduit 63 leading to the reservoir 51. Thus, with the valve element 59 in the lowered position shown in Figure 6, fluid under pressure will be admitted to the lower ends of the cylinders 46, 46, causing the pistons 47 to be elevated, whereby the arms 15 and the digging wheel structure 33 will be elevated. Conversely, when the valve element 59 is raised, as by rotating the valve operating handle 65 clockwise from the position shown in Figure 6, the upper port 60 will be placed in communication with the fluid inlet port 55 and the lower port 57 will be placed in communication with the fluid return passage 61. This will cause hydraulic fluid under '4 pressure to be admitted into the top ends of the cylinders 46, 46 and will allow hydraulic fluid to discharge from the lower ends of said cylinders, causing the piston rods 47 to be lowered, and thus causing the arms 15 and the digging wheel structure 33 to be similarly lowered.

Designated at 66 is a second three-way valve having the fluid inlet port 67, the lower port 68 and the upper port 69. When the movable valve element 70 is in its lowered position, shown in Figure 6, the fluid port 68 is connected to the port 67. Port 67 is connected by a conduit 71 to the conduit 52. Port 68 is connected by a conduit 73 to the lower end of the cylinder 29. Port 69 is connected by a conduit 74 to the upper end of the cylinder 29. Valve 66 is provided with the return passage 75 which is connected by a conduit 76 to the return conduit 63. When the valve element 70 is in its lowered position, shown in Figure 6, hydraulic fluid under pressure will be delivered from the port 67, through the port 68 and the conduit 73, to the lower end of the cylinder 29. Hydraulic fluid will discharge from the upper end of said cylinder through the conduit 74, the port 69, the return passage 75 and the conduit 76 to the return conduit 63, whereby the return fluid is delivered to the reservoir 51. This causes the piston rod 30 to be elevated, whereby the frame 20 will be rotated clockwise, as viewed in Figure 2. To rotate the frame counterclockwise, as viewed in Figure 2, the valve operating handle 77, linked to the valve element 70, is rotated clockwise, as viewed in Figure 6, to elevate the valve element 70, reversing the direction of the hydraulic fluid in the conduits 73 and 74, and causing hydraulic fluid under pressure to enter the conduit 74, and thus to enter the top end of the cylinder 29, while at the same time hydraulic fluid is discharged from the lower end of the cylinder 29 into the return passage 75, and thence to the return conduits 76 and 63. When the piston rod 30 is lowered, the frame 20 is rotated counterclockwise, as viewed in Figure 2.

From the above it will be seen that the operating levers 65 and 77, associated with the valves 54 and 66 mounted on the tractor provide a means whereby the operator of the tractor may regulate the raising and lowering of the digging wheel structure 33, and at the same time the angle of elevation of the conveyor 32.

Thus, the raising and lowering of the digging wheel structure 33 is controlled by the valve operating handle 65, whereby the digging wheel structure 33 may be moved to a desired position. In order to level the conveyor 32 the valve operating handle 77 may be manipulated to properly adjust the position of frame 20 to adjust the conveyor to a horizontal position.

Referring now to Figure 5, it will be seen that the tractor is provided with three serially arranged, conventional multiple-ratio transmission sections, shown at 78, 79 and 80, for example, each having four forward speed ratios. The crankshaft 81 of the engine 50 is connected through the conventional clutch 82 to the input shaft 83 of the first transmission section 78. The output shaft 84 of the first section is directly coupled to the input shaft 85 of the second section 79, and the output shaft 86 of the second section 79 is directly coupled to the input shaft 87 of the third section 80. The output shaft of the third section 88 is connected directly to the differential input shaft 88 which is conventionally coupled to the traction means 13 of the tractor. Each of the multiple-ratio transmission sections 78, 79 and 8-8 is provided with the usual gear shift lever, the levers being shown at 89, 90 and 91 in dotted view in Figure 5, whereby the speed of the tractor may be controlled over a wide range of different values, depending upon the positions of the gear shift levers 89, 90 and 91. The combinations of different ratios provided by the three serially arranged transmission units 78, 79 and 80 thus provide a selection of tractor speeds ranging from a low speed of the order of 18 inches per minute to the top speed of the tractor.

Mounted on the tractor frame is an additional multiplefour forward speed ratios, said unit having the input shaft 93 and the output shaft 94, the selection of speed ratios being controlled by the operation of the transmission gear shift lever 95, shown in dotted view in Figure 5. Suitably journaled in the top portions of upstanding supports 96 and 97 secured on the transmission units 78 and 79 are respective shaft elements 99 and 98 which are coupled together by a conventional clutch 100, said clutch being controlled by the clutch handle 101. The shaft 99 is drivingly coupled to the transmission shafts 84 and 85 between the first and second transmission units 78 and 79, as by sprocket chains 102 engaging sprocket wheels on the shafts 8485, as illustrated in Figure 5, whereby the shaft 99 is driven by the intermediate transmission shafts 84 and 85 between the first transmission section 78 and the second transmission section 79. The shaft 98 is connected to the input shaft 93 of the auxiliary transmission unit 92 by a universal joint 104, as shown in Figure 5, thus allowing relative movement between the transmission unit 92 and the transmission units 78 and '79. It will be also observed from Figure 5 that the output shaft 86 of transmission unit 79 is coupled to the input shaft 87 of the transmission unit 80 by a flexible coupling 105 which allows small relative angular movements of the shafts 86 and S7.

The auxiliary transmission unit 92 includes a differential comprising respective transverse shafts 106 each having a large beveled gear 107 secured thereon which i in mesh with a pinion gear 108 carried on the shaft 94, whereby the shafts 106 are driven by the output shaft 94 of the transmission unit 92. Secured on each shaft 106 externally of the housing of the transmission unit 92 is a sprocket wheel 109 which is coupled to a respective sprocket wheel 19 by a sprocket chain 110.

As shown in Figure 2, each sprocket chain 110 is tensioned by a tension arm 111 pivoted to the tractor frame in any suitable manner and biased upwardly by a spiral spring 112 having its outer end connected to the end of the tensioning arm 111 and having its inner end anchored to the tractor frame, the end of the tensioning arm bearing against the upper portion of the sprocket chain 110 and exerting tensioning force on said chain, as will be readily apparent from Figure 2.

In operation, the traction element 13 of the machine is driven at a selected rate of speed from the engine 58 through the serially arranged multiple-ratio transmission units 78, 79, and 80. At the same time the sprocket chains 110 are driven at a selected speed through the multiple-ratio transmission units 78 and 92, assuming the clutch 100 to be in engaged position whereby torque is transmitted from shaft 99 to shaft 98. This rotates the shaft 18, causing the digging wheel structure 33 to be rotated clockwise, as viewed in Figure 2, whereby the digging buckets 38 penetrate into the soil to an increasing depth as the digging action continues, assuming the digging wheel 33 to be lowered to ground-engaging position, and whereby the excavated soil is elevated by the buckets 38 and is deposited on the moving belt of the conveyor 32 continuously. The excavated soil is moved laterally on the moving conveyor belt and is deposited into a truck or other vehicle disposed subjacent the end of the conveyor belt, as above described.

As shown in Figure 3, the machine may be employed on a downward grade, the machine moving downwardly along the grade, whereby the trench is excavated in a downward direction. Similarly, the machine may be employed to excavate along an upward grade, as shown in Figure 4.

The tractor may be suitably countereighted to counter-balance the weight of the digging wheel structure 33 and the other elements associated with the digging attachment, as by the provision of a receptacle 112 on the end of the tractor opposite the digging attachment, said receptacle being employed to receive suitable weights, tools, or other heavy items.

From the above it will be apparent that the digging wheel structure may be raised and lowered by hydraulicjack cylinders 46, which are in turn controlled by the valve operating lever 65. It will also be apparent that the cylinders 46 govern the digging pressure and may be employed to force the digging wheel bucket elements 38 into the ground with a maximum pressure equal to that which can be developed by the weight of the tractor. It is apparent that the maximum grades which can be worked by the machine can be increased by suitably increasing the length of the hydraulic cylinders 46, whereby the range of angular movement of the arms 15, 15 may be accordingly increased.

The digging wheel elements 37, 37 are preferably solid castings, eliminating the necessity for welding separate segments together, reducing irregularities, minimizing wear, .and obtaining smoother operation than has been heretofore obtained with welded digging wheel elements.

The hydraulic motors, not shown, which drive the conveyor shaft 35 are of conventional construction and are preferably operated by the tractor engine 50, through suitable hydraulic pump means. As above explained, the speed of the conveyor belt can be thus adjusted to the needs of the digging operation. For example, in soft soil, the speed of the belt may be accelerated to handle the increased amount of soil deposited on the conveyor belt by the digging buckets 38.

While a specific embodiment of an improved excavating machine has been disclosed in the foregoing description, it will be understood that various modifications within the spirit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

1. In combination, a tractor, a pair of arms pivoted at their ends to opposite sides of the tractor and extending upwardly and longitudinally thereof, a transverse shaft mounted in the opposite ends of said arms, upstanding means rigidly connecting the intermediate portions of said arms, a frame rotatably mounted on said shaft between said arms and having an end portion extending subjacent the top of said upstanding means, link means connecting said frame portion to the top of said upstanding means, a digging wheel rotatably supported on the intermediate portion of said frame for rotation around a transverse axis, said wheel being provided with digging buckets on its periphery, a belt conveyor mounted on said frame within and transverse to said wheel, jack means connected between the tractor and said arms for raising and lowering said arms, and means on the tractor drivingly coupled to said digging wheel and arranged to rotate said digging wheel.

2. In combination, a tractor, a pair of arms pivoted at their ends to opposite sides of the tractor and extending upwardly and longitudinally thereof, a transverse shaft rotatably mounted on the opposite ends of said arms, upstanding means rigidly connecting the intermediate portions of said arms, a frame rotatably mounted on said shaft between said arms and having an end portion extending subjacent the top of said upstanding means, adjustable link means connecting said frame portion to the top of said upstanding means and arranged to vary the angu-.

lar relation between said frame and said arms, a digging wheel rotatably supported on the intermediate portion of said frame for rotation around a transverse axis, said wheel being provided with digging buckets on its periphery, a belt conveyor mounted on said frame within and transverse to said wheel, jack means connected between the tractor and the portions of said arms adjacent the tractor for raising and lowering said arms, means gearingly coupling said shaft to said wheel, and means on the tractor drivingly coupled to said shaft and arranged to rotate said shaft.

3. In combination, a tractor, a pair of arms pivoted at their ends to opposite sides of the tractor and extending upwardly and longitudinally thereof, a transverse shaft rotatably mounted on the opposite ends of said arms, upstanding means rigidly connecting the intermediate portions of said arms, a frame rotatably mounted on said shaft between said arms and having an end portion extending subjacent the top of said upstanding means, a hydraulic link connecting said frame portion to the top of said upstanding means and arranged to vary the angular relation between said frame and said arms, a digging wheel rotatably supported on the intermediate portion of said frame for rotation around a transverse axis, said Wheel being provided with digging buckets on its periphery, a belt conveyor mounted on said frame within and transverse to said wheel, said conveyor extending substantial distances laterally on opposite sides of the tractor, respective hydraulic jacks connected between the tractor and the portions of said arms adjacent the tractor for 3; raising and lowering said arms, means gearingly coupling said shaft to said wheel, and means on the tractor drivingly coupled to said shaft and arranged to rotate said shaft.

References Cited in the file of this patent UNITED STATES PATENTS 2,084,887 Bennett June 22, 1937 2,321,352 Askue June 8, 1943 2,488,990 South Nov. 22, 1949 2,598,339 Askue May 27, 1952 2,648,145 Askue Aug. 11, 1953 2,747,307 Griflin May 29, 1956 FOREIGN PATENTS 677,671 Great Britain Aug. 20, 1952 OTHER REFERENCES Unit Rig and Equipment Company, Trencher, found on page 110 of the July 20, 1950, issue of Engineering News-Record. 

